Famed naturalist John Muir (1838-1914) came to Wisconsin as a boy and studied at the University of Wisconsin. He first came to California in 1868 and devoted six years to the study of the Yosemite Valley. After work in Nevada, Utah, and Colorado, he returned to California in 1880 and made the state his home. One of the heroes of America's conservaton movement, Muir deserves much of the credit for making the Yosemite Valley a protected national park and for alerting Americans to the need to protect this and other natural wonders. My first summer in the Sierra (1911) is based on Muir's original journals and sketches of his 1869 stay in the Sierras. Hired to supervise a San Joaquin sheep owner's flock at the headwaters of the Merced and Tulomne Rivers, Muir sets out for the mountains in June, returning to the Valley in September. He describes the flora and fauna of the mountains as well as his visits to Yosemite and his climbs of Mt. Hoffman and other peaks in the range.